Ajax request failure in Safari with error 403 (Forbidden)

Ajax request failure in Safari with error 403 (Forbidden)

hi there,
i'm using ST2 MVC for my app.
I using Ext.Ajax.request for get/post data with Cakephp 1.3 service backend.
It work fine on Google Chrome but on Safari i get error 403 (Forbidden)
Any help for me!